Float operated switch



March 9- A. N. COLYER ET AL 2,465,516

FLOAT OPERATED SWITCH Filed Feb. 23, 1946 Inventors ALBERT N. COLYER NELSON F COX B M y a Attorney.

' Patented Mar. 29, 1949 UNITED STATES PATENT OFFICE FLOAT OPERATED SWITCH Albert N. Colyer and Nelson F. Cox, Winnipeg, Manitoba, Canada Application February 23, 1946, Serial No. 649,587

1 Claim. 1

This present invention relates to improvements in a safety device in connection with level of cooling and lubricating liquids.

An object of the invention is to provide a safety device especially designed for use with motor vehicles and responsive on the falling of the level of either the cooling or lubricating liquid to opcrate a warning signal and, if this is not heeded, on the further dropping of the liquid level to the danger point to interrupt the ignition circuit thus bringing the motor to a stop before serious damage is done.

A further object of the invention is to provide a safety device for liquid levels embodying a novel float-actuated mechanism controlling two circuits that are successively operated on the falling of the liquid level with a suitable time lag so that the warning signal operated by the first circuit may be heeded and the liquid replenished to restore the proper level before the time occurs for the second circuit to be affected.

A further object of the invention is to provide a liquid level safety device wherein a switch box surmounts the float chamber and the circuit closers and/or breakers are actuated by a vertically sliding float carried stem.

A further object of the invention is to provide a float operated circuit controlling safety device for liquid levels wherein the float containing chamber is normally closed at the top except for an upwardly rising overflow pipe thus allowing the system to hold a substantial excess or reserve of liquid that may safely be expended without affecting the operation of the circuit switches.

A still further object of the invention is the provision of a liquid level safety device that may be attached directly in a threaded opening through an engine block, radiator, crank case, or the like, otherwise providing its own support and eliminating the need of extraneous parts or fittings or requiring any work to be done on or changes made in the engine structure, per se.

A yet further object of the invention is the provision of a safety device in connection with the level of cooling and/or lubricating liquids of the nature and for the purposes set forth, that is characterized by structural simplicity, durability, and operative efiiciency, positive and reliable in operation and being capable of production at reasonable cost is thereby rendered commercially desirable.

To the accomplishment of these and related objects as shall become apparent as the description proceeds, the invention resides in the construction, combination and arrangement of parts 5 as hereinafter more fully described, illustrated in the accompanying drawings, and pointed out in the claim hereunto appended.

The invention will be best understood and can be more clearly described when reference is had to the drawings forming a part of this disclosure wherein like characters indicate like parts throughout the several views.

In the drawings:

Figure 1 is a sectional elevation of a possible embodiment of the invention with the float chamber and lower parts shown in section on the lateral median and the switch box surmounting the same mostly in elevation with the slide face plate broken away; and

Figure 2 is a side elevation of the device as seen at right angles to Figure 1.

The simple and preferred form of our invention illustrated herein consists of a short pipe I threaded at both ends 2 and 3, the lower to engage a threaded bore through the engine head into the cooling chamber, and the upper end to re-- ceive a flared coupling 4 interiorly threaded at its upper end to receive the exteriorly threaded bottom edge 5 of the float chamber cylinder 6. The upper rim of this cylinder is outwardly flanged as at I overlying which is a sealing disk or cover 8. A brass valve seat 9 is inserted in a central perforation ID in the cover 8 which valve seat is in turn provided with a central bore II. A float I2 is housed in the cylinder 6 having an upstanding rod-like stem I4 rising from the centre of the top thereof that passes freely through the bore II in the brass valve seat 9. To seal this stem passing bore I I against leakage when the cylinder 6 is full to overflowing, a rubber seat washer I5 surrounds the stem I 4 just above the float and on such occasions sealingly engages the brass valve seat 9. Provision for an excess or ample reserve of liquid over the float level is by way of an overflow or outlet tube I6 that rises from the cylinder 6 through the cover disk 8 near the back thereof.

Surmounting the float chamber 6 and prefei ably spaced above it as by the arcuate supporting legs Ii, that fasten to the cylinder flange I by the nut and bolt assemblies I8 that pass through and also secure the cover disk 8, is an open face switch box I 9 provided with an upwardly sliding, slightly inclined front cover plate 20. This box surrounds the vertically standing centre float rod I4 and is disposed in advance of the overflow tube I6, as shown in Figure 2. The float stem I4 is steadied near its upper end by a perforated angle bracket 2| mounted on the inside of the back of the switch box I9. This rod or stem I4 carries a vertically adjustable sleeve 22 with a tapered or bevelled lower end 23, that is secured in the desired position on said stem by a set screw 24.

A pair of micro or other suitable snap-action switches 25 and 26 each with one terminal grounded are located in the box 20, one on either of the stem 14 with their respective depending controlling or rocker arms 21 each terminally carrying a U-shaped bracket 28 mounting an inwardly facing, freely rotatable wheel or roller bushing 29 normally engaging opposite sides of the stem M with that roller 29 being carried by the switch 25 at a point above that carried by the other switch 26 and both at a point below the bevelled lower end 23 of the stem-carried sleeve 22 when float is in its uppermost position.

Lead wires 30 and 3| from the respective switches 25 and 26 are carried to a pair of insulated binding posts 32 and 33 passing out through the side of the box and beyond an insulating plate 3 1 on the outside thereof where lead wires 35 and 3t carry the circuits from the switches 25 and 26 respectively to a warning signal and an ignition interrupter.

Thus while the liquid level stands high in the cylinder or extends well up the overflow or relief tube It, the float 12 with its washer l5 seals the bearing valve 9 against leakage and the stemcarried switch-actuating sleeve 22 is held above engagement with the vertically-offset pair of rollers 29 on the switch-throwing rocker arms 23. its the liquid level drops, however, the falling of the float causes the stem-carried sleeve to engage the upper rock-er arm roller 29 throwing the switch 25 which we intend through the lead wires 29 and 35, in one or the motor vehicles grounded electric circuit, to flash or sound a warning signal wired in series therewith and to continue such signal until the dwindling liquid replenished and a safe level restored when the rising float causes the release of the switch throw. Should the operator fail to heed the audible or visible signal and continue to operate the vehicle until the liquid level falls farther and reaches the level at which further operation of the motor will likely result in damage to the same, the stemcarried sleeve 22 engages the second or lower roller 29 on the rocker arm of switch 26 and hrowing the same cuts oh the motors ignition through the lead wires SI and 36. This latter may be by shorting or grounding the ignition circuit and breaking the same by blowing a fuse through the operation of a circuit interrupting relay, as may be desired. Since the instant form of signal and the chosen means of interrupting the ignition circuit are matters known to all and well within the choice of anyone skilled in this art the selection does not alter the form of the present float operated switching device, they are not here shown nor described in detail but it is to be understood that a supply of liquid, electric circuits and a source of electricity are essentials to the operation of our safety device.

While the herein illustrated and described form of liquid level operated safety device is intended primarily for the cooling system of an internal combustion engine, being designed to be screwed into a threaded bore in the cylinder head of a motor such as is commonly used in buses, trucks, automobiles and the like, it is equally applicable as is or with minor changes to the crank cases or lubricating oil reservoir of similar or other kinds of motors, engines and machines of various kinds where continued operation after a predetermined fall in the liquid level may result in danger, damage or loss.

From the foregoing description taken in connection with the accompanying drawings, it will be manifest that a safety device in connection with level of cooling and lubricating liquids is provided that will fulfil all the necessary requirements of such a device, but as many changes could be made in the above description and many apparently widely difierent embodiments of the invention may be constructed within the scope of the appended claim without departing from the spirit or scope thereof, it is intended that all matters contained in the said accompanying specification and drawings shall be interpreted as illustrative and not in a limitative or restrictive sense.

Having thus described the invention, what is claimed as new and desired to secure by Letters Patent is:

A safety device for liquid levels comprising in combination with a liquid receiving cylinder, a switch box surmounting said cylinder and a float in said cylinder with a stem rising therefrom into said switch box, a vertically spaced pair of switches in said box both relatively near the bottom thereof, a rocker arm extending from each switch toward said float stem and a switchthrowing member on said stem normally positioned above the uppermost of said switches and on falling engageable successively with first the upper and then the lower of said switch rocker arms respectively, said switch-throwing member being in the form of a vertically adjustable sleeve bevelled on its lower end and of a greater length than the vertical spacing between the switch rocker arms.

ALBERT N. COLYER. NELSON F. COX.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 

